Keying device for phase reversal



g- 25, 1942' R. VON OTTENTHAL 2,294,103

KEYING .DEVICE FOR PHASE REVERSAL Filed March 1, 1941 2 Sheets-Sheet l 4AW 7 [M144 JNVENTOR.

1942- R. VON OTTENTHAL 2,294,103

KEYING DEVICE FOR PHASE REVERSAL Filed March 1, 1941 2 sheets-sheet 2FIG. 3b..

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1 Q Q Q 1 L! Q l 1 I Patented Aug. 25, 1942 s'rrs KEYING DEVICE FORPHASE REVERSAL Rudolf von Ottenthal, Berlin, Germany, assignor to C.Lorenz Aktiengesellschaft, Berlin-Tempelhof, Germany, a companyApplication March 1, 1941, Serial No. 381,333 In Germany February 16,1940 1 1 Claims.

This invention relates to keying devices and has for its object toprovide a symmetric reversing device which serves to reverse with theaid of a unipolar switch the phase of two energy that the polarity ofthe energy line is reversed by 180, and that further in each branchconductor always reactances of the same magnitude are located. Thearrangement may be such that the current path of one branch conductorbiiurcates in two reactances of the same magnitude and phase and that,depending upon the position of the switch, one reactance is released tobe traversed by currents while the other is ren- 1 dered ineffective bya resonant circuit arrangement and vice versa.

In the drawings, Fig. 1 is a diagram showing the novel network employedfor phase reversal.

Fig. 2 is a diagram illustrating the circuit ar-" rangement of atransmitter in which the novel phase reversing device serves-forreversing the phase conditions of the reflecting antennae of adirectional antenna system. Figs. 3a, 3b, 30 represent substitute orequivalent circuits with theunipolar switch in difierent positions. Fig.

4 shows the substitute circuit that serves for calculating the operationof the switch. Fig. 5

is a diagrammatic view of an arrangement whose reversing switch is arotating plate condenser.

In Fig. 1, I and 2 denote the branch conductors whose phase is reversedby network as provided by the invention. At [5, conductor 2 bifurcatesin two reactances l4, 5 of the same magnitude and phase, As shown by wayof example, such reactances may be coils or inductances.

The coils l4, 5 are alternately rendered inefiective with respect toconductor 2 by a switch S by which a reactance 6, such as a condenser,is connected in parallel with either coil! or coil 5. With the switch Sin position I condenser [E is connected in parallel with coil [4, theparallel resonant circuit so formed constituting a high resistance forconductor 2. The current of conductor 2 will therefore flow over coils5, I while the current of conductor 1 passes over the switch S and coil8. By turning the switch S into the position'II the condenser 6 isconnected in parallel with coil 5, whereby the current of Such networkis under the control of a.

conductor 2 flows over coils l4, 8 while the current of conductor 1passes over switch S and coil 7.

Fig. 3a is the substitute diagram of the net- 5 work with switch S inposition I. Fig. 3b is the substitute diagram of the network with switchS in position II. Fig. 3c is the'substitute diagram relating to themid-position M of the switch.

In conductor I, Fig. 1, a reactance or coil 9 is included which is toprovide for an entirely symmetric construction of the phase reversingdevice, that is to say, a construction having resistances of the samemagnitude located in each branch conductor, whether switch S be inposition I or position II. The network as a whole has the surgeimpedance Z. Owing to the entirely symmetric construction of the networkthe casing may be atearth potential in order to obviate disturbancescaused by the consuming apparatus joined to the phase reversing device.Connected in parallel with the contacts of S is a condenser in that actsto neutralize the capacity of switch S. I

With switch S in its mid-position M the reactances 6, 9 are connected inseries and thus constitute a series resonant circuit by which theconductors I, 2 areshort-circuited. Consequent- 1y, whenever thechange-over switch S moves from one position to the other no energyarrives at the outgoing lines 3, 4.

The reactance l0, constituted by a condenser, for instance, is locatedbehind switch S while the reactances l, 8, which for example are coilsor inductances and are in phase opposition, are included in the outgoinglines 3, 4. The entire network has the reactance Z.

CALCULATION or SURGE IMPEDANCE AND PHASE RATE or THE PHASE REVERSINGDEVICE 0 r (1) Short-circuiting resistance 4n a =7r arc. tr

are no losses. Input power:

The advantages of the symmetric phase reversing device are as follows:

(1) This device maybe constructed to be perfectly symmetric with respectto the casing.

(2) The current under the control of switch S is the nth part of thecurrent passing through the consuming device. Thus, a'comparativelysmall reversing device will be able to effect the phase reversal of highpower currents. For instance, in theshort wave range a reduction on thebasis of n= may be employed without difficulty.

(3) The capacity due to the reversing device is harmless.

The novel phase reversing device is suitable especially for use withtransmitters employed is the energy effective in a directional antennasystem which, for instance, is comprised of directional radiators E, F,such superposition being in phase coincidence and phase oppositionalternately. The phase reversal in the antenna conductors E, F iseffected by means of the phase reversing device according to the inven-'tion.

If it is desired not to key the antenna system in the rhythm ofcomplementary signals but, for instance, to distinguish between theresultant directional characteristics with the aid of modulatingfrequencies, then according to another feature of the invention, theunipolar changeover switch is a rotating plate condenser arranged tocooperate with different modulators.

In Fig. 5, which shows an example of arrangements of the latter kind,the stator plates I, II of the rotating plate condenser K are connectedto the lines 3, i. The stator plates are designated I, II because theyagree in position with the positions I, II, Figs. 1 and 2, the rotor IIIof condenser K having the office of the switch S. For instance, wheneverthe rotor is facing the plate I,'the conditions are the same as in thecase of switch S, Fig. 1, having the position I. Equally, position II ofswitch S agrees with the rotor facing the plate II.

This arrangement, however, is disadvantageous inasmuch as the residualcapacities of the condenser K are still effective.

In order to overcome this drawback, inductances l i, 12 are arranged inadvance of condenser K and between the lines 3, 4, while an inductanceI3 is connected in series with rotor III. The inductances Ii, I2, i3 arecalculated to neutralize the residual capacity of condenser K. Theresidual capacity of this condenser is designated jYB. With the rotorIII facing plate I, as shown, this residual capacity and the inductancel3 constitute a short-circuit arrangement, while such residual capacityand the inductance l2 constitute a trap circuit for high frequencycurrents. Accordingly, with rotor III facing plate I, the currentarriving from conductor 2 flows only over the coils 5, I while thecurrent from conductor I passes only over condenser K and coil 8.

Whenever the rotor is facing the plate II, the conditions are thereverse of the former.

Mounted on the shaft of rotor III is a contact arm forming part of aswitch P which thus depends in its action on the position of :the rotor.Switch P acts to alternately connect two different modulators to thetransmitter.

Condenser K may be employed also for'keying in the rhythm ofcomplementary signals. In such case, however, the stator plates must beof a special construction.

What is claimed is:

1. A circuit arrangement having an energy line that comprises twoconductors, a network included in this line and comprising reactances, aunipolar change-over switch adapted to switch this network and therebyto reverse the polarity of said energy line by one of the said conductors being bifurcated into two of the said reactances so as to formtwo outgoing lines, these two reactances beingof the same magnitude andphase, and means, under control ofv the said switch, for establishingresonant circuits adaptedto neutralize eitherone or'the otherofthe saidtwo reactances.

2. An arrangement according to claim 1,

'wherein the means for establishing reasonant circuits comprises areactance in phase opposition to the said two reactances and arranged inbridge of the said conductors, this reactance being arranged to beconnected in parallel with these two reactan-ces by said switch.

3. An arrangement according to claim 1, having a reactance in bridge ofthe said outgoing lines, a reactance included in one of these lines, anda reactance included in the other outgoing line.

4. An arrangement according to claim 1, wherein the said two reactancesare inductances of the same magnitude and wherein the means undercontrol of the switch for establishing resonant circuits comprises acondenser.

5. An arrangement according to claim 1, wherein an inductance isincluded in the conductor of the energy line which is not bifurcatedinto said reactances.

6. An arrangement according to claim 1, having a condenser in bridge ofsaid outgoing lines, an inductance included in one of these lines, andan inductance included in the other outgoing line.

'7. An arrangement according to claim 1, wherein the unipolar switch isa rotating plate condenser comprised of a rotor and two stator plates,one of these plates being joined to one of said outgoing lines and theother stator plate being connected to the other outgoing line.

8. An arrangement according to claim 1, comprising a rotating platecondenser which constitutes the unipolar switch, this condenser beingcomprised of a rotor and two stator plates, one of these plates beingjoined to one of said utgoing lines and the other stator plate beingconnected to the other outgoing line. two inductances located in advanceof this condenser and between said outgoing lines, and a thirdinductance, these three inductances being calculated to neutralize theresidual capacity of said condenser,

9. An arrangement according to claim 1, wherein a radio transmitter isconnected to said energy line, and wherein the unipolar switch is arotating plate condenser comprised of a rotor and two stator plates, oneof these plates being joined to one of said outgoing lines and the otherstator plate being connected to the other outgoing line, means formodulating the energy from said transmitter, said means comprising twosources of current having different frequencies, means for connectingone of said sources to said rotor plate only during the part of itscycle in which it is operatively associated with a first one of saidstator plates, and means to connect the other source to said rotor plateonly while it is operatively associated with the other stator plate.

10. An arrangement according to claim 1, comprising a rotating platecondenser which constitutes the unipolar switch, this condenser beingcomprised of a rotor and two stator plates, one of these plates beingjoined to one of said outgoing lines and the other stator plate beingconnected to the other outgoing line, a switch having a rotary contactarm, a shaft common to this contact arm and said rotor, two modulatorsoperating at difierent frequencies, a pair of stationary contact memberseach connected to one of said modulators, said contact memberscorresponding in length and position to said stator plates and beingdisposed so as to be contacted by said contact arm as it rotates, thearrangement being such that the current from said energy line ismodulated alternately by two difierent frequencies.

11 An arrangement according to claim 1, wherein a reactance is connectedin series with the conductor of the energy line which is not bifurcatedinto said reactances.

RUDOLF VON OTTENTHAL.

